Method, base station and user equipment for subframe configuration in time division duplex system

ABSTRACT

Disclosed are a method, a base station and a user equipment for subframe configuration in a time division duplex system. The method comprises: a base station determining a subframe number of a flexible subframe in a radio frame; the base station determining a feature of the flexible subframe corresponding to the subframe number, where the feature indicates that the flexible subframe is an uplink subframe or a downlink subframe; and the base station sending to a user equipment a first signaling via a downlink control channel, where the first signaling includes the feature of the flexible subframe corresponding to the subframe number.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2012/073437, filed on Mar. 31, 2012, which claims priority toChinese Patent Application No. 201110081085.7, filed on Mar. 31, 2011,both of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communicationstechnologies, and more particularly to a method, a base station and auser equipment for subframe configuration in time division duplexsystem.

BACKGROUND

A long term evolution (LTE, Long Term Evolution) system supports timedivision duplex (Time Division Duplexing, TDD), that is, an uplink (UL,Uplink) and a downlink (DL, Downlink) use different time slots on thesame frequency. The LTE TDD system can semi-statically configureuplink-downlink configuration (Uplink-Downlink Configuration) accordingto a traffic type, so as to satisfy different uplink-downlink asymmetrictraffic demands. In the LTE TDD system, the adopted uplink-downlinkconfiguration is configured semi-statically, and cannot be changeddynamically, which leads to a mismatch between a current uplink-downlinkconfiguration and an instantaneous uplink-downlink traffic amount, andthus resources cannot be effectively used, which is particularly seriousfor a cell with less number of users.

In order to solve the above problem, a concept of dynamic TDD subframeconfiguration has been introduced, that is, some flexible subframes areconfigured in a radio frame, where each flexible subframe can bedynamically configured to be an uplink subframe or a downlink subframe.

In the prior art, however, a user equipment cannot acquire features ofthe flexible subframes in the scenario of the dynamic TDD subframeconfiguration and, thus, cannot subsequently perform data interactionwith the base station according to the features.

SUMMARY

Embodiments of the present invention provide a method, a base stationand a user equipment for subframe configuration in a time divisionduplex system, so as to solve the problem in the prior art that the userequipment cannot know whether a flexible subframe is an uplink subframeor a downlink subframe.

In order to solve the above technical problem, embodiments of thepresent invention provide a method for subframe configuration in a timedivision duplex system, comprising:

determining, by a base station, a subframe number of a flexible subframein a radio frame;

determining, by the base station, a feature of the flexible subframecorresponding to the subframe number, where the feature indicates thatthe flexible subframe is an uplink subframe or a downlink subframe; and

sending, by the base station, to a user equipment a first signaling viaa downlink control channel, where the first signaling includes thefeature of the flexible subframe corresponding to the subframe number.

Embodiments of the present invention provide a base station, comprising:

a first processing unit, configured to determine a subframe number of aflexible subframe in a radio frame;

a second processing unit, configured to determine a feature of theflexible subframe corresponding to the subframe number determined by thefirst processing unit, where the feature indicates that the flexiblesubframe is an uplink subframe or a downlink subframe;

a sending unit, configured to send to a user equipment a first signalingvia a downlink control channel, where the first signaling includes thefeature of the flexible subframe corresponding to the subframe numberdetermined by the second processing unit.

Embodiments of the present invention provide a method for subframeconfiguration in a time division duplex system, comprising:

acquiring, by a user equipment, a subframe number of a flexiblesubframe;

receiving a first signaling sent by a base station via a downlinkcontrol channel, where the first signaling includes a feature of theflexible subframe corresponding to the subframe number, and the featureindicates that the flexible subframe is an uplink subframe or a downlinksubframe;

acquiring, according to the received first signaling, the feature of theflexible subframe corresponding to the subframe number.

Embodiments of the present invention provide a user equipment,comprising:

a fourth processing unit, configured to determine a subframe number of aflexible subframe;

a receiving unit, configured to receive a first signaling sent by a basestation via a downlink control channel, where the first signalingincludes a feature of the flexible subframe corresponding to thesubframe number determined by the fourth processing unit, and thefeature indicates that the flexible subframe is an uplink subframe or adownlink subframe;

an acquiring unit, configured to acquire, according to the firstsignaling received by the receiving unit, the feature of the flexiblesubframe corresponding to the subframe number.

Embodiments of the present invention have advantages as follows:

in the embodiments of the present invention, a base station can notify auser equipment of feature configuration of a flexible subframe by way ofsignaling via a downlink control channel, so that the user equipment canknow the feature of the flexible subframe, and then can communicatenormally with the base station on the flexible subframe based on thefeature of the flexible subframe.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the technical solution of the present invention or theprior art more clearly, the accompanying drawings used in description ofthe embodiments of the present invention or the prior art are brieflydescribed hereunder. Apparently, the accompanying drawings illustrateonly some embodiments of the invention and persons skilled in the artcan derive other drawings from these drawings without any creativeeffort.

FIG. 1 is a flow chart of a method for subframe configuration in a timedivision duplex system according to a first embodiment of the presentinvention;

FIG. 2 is a schematic diagram of a dynamic TDD subframe configuration ina radio frame according to an embodiment of the present invention;

FIG. 3 is a flow chart of a method for subframe configuration in a timedivision duplex system according to a second embodiment of the presentinvention;

FIG. 4 is a schematic structural diagram of a base station in a timedivision duplex system according to a first embodiment of the presentinvention;

FIG. 5 is a schematic structural diagram of a sending unit of a basestation according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a sending unit of a basestation according to another embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a sending unit of a basestation according to another embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a base station in a timedivision duplex system according to a second embodiment of the presentinvention;

FIG. 9 is a flow chart of a method for subframe configuration in a timedivision duplex system according to a third embodiment of the presentinvention;

FIG. 10 is a schematic structural diagram of a user equipment in a timedivision duplex system according to a first embodiment of the presentinvention;

FIG. 11 is a flow chart of a method for subframe configuration in a timedivision duplex system according to a fourth embodiment of the presentinvention;

FIG. 12 is a schematic structural diagram of a base station in a timedivision duplex system according to a third embodiment of the presentinvention;

FIG. 13 is a schematic structural diagram of a base station in a timedivision duplex system according to a fourth embodiment of the presentinvention;

FIG. 14 is a flow chart of a method for subframe configuration in a timedivision duplex system according to a fifth embodiment of the presentinvention;

FIG. 15 is a schematic structural diagram of a user equipment in a timedivision duplex system according to a second embodiment of the presentinvention; and

FIG. 16 is a schematic structural diagram of a user equipment in a timedivision duplex system according to a third embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENTS

The technical solutions in embodiments of the present invention arehereinafter described clearly and completely with reference to theaccompanying drawings in embodiments of the present invention.Evidently, the embodiments described here are only a part of theembodiments of the invention, rather than all of the embodiments of theinvention. All other embodiments obtained by persons skilled in the artbased on the embodiments of the present invention without any creativeeffort shall fall within the protection scope of the invention.

In order to make the above object, features, and advantages ofembodiments of the present invention more comprehensible, embodiments ofthe present invention are hereinafter described in detail with referenceto the accompanying drawings and specific implementations of the presentinvention.

There are altogether seven types of uplink-downlink configurations in aLTE TDD system, as shown in Table 1, where ‘D’ indicates a downlinksubframe, ‘U’ indicates an uplink subframe, and ‘S’ indicates a specialsubframe, which is mainly used for downlink transmission. Seen fromTable 1, for each uplink-downlink configuration, the time domainresource reserved for the downlink traffic takes up 40% to 90%.

TABLE 1 Configura- Repeating Subframe number tion number period 0 1 2 34 5 6 7 8 9 0 5 ms D S U U U D S U U U 1 5 ms D S U U D D S U U D 2 5 msD S U D D D S U D D 3 10 ms  D S U U U D D D D D 4 10 ms  D S U U D D DD D D 5 10 ms  D S U D D D D D D D 6 5 ms D S U U U D S U U D

The flexible subframe in the context of the present invention refers toa subframe that can be dynamically or semi-statically configured to bean uplink subframe or a downlink subframe within a valid time of eachTDD uplink-downlink configuration. For user equipment of an existingversion, such as user equipments of LTE Rel-8/9/10, the system notifiesthe current seven types of uplink-downlink subframe configurations via abroadcast signaling; for user equipment of an evolution system, such asthe user equipment of LTE Rel-11/12 etc., the system can semi-staticallyor dynamically notify different uplink-downlink subframe configurations,which can be the existing seven types of configurations, also can be anewly added uplink-downlink subframe configuration, for example, whenthe existing system and the evolution system both notify according tothe existing seven types of configurations, subframes 3, 4, 5, 6, 7, 8and 9 can be considered to be flexible subframes, and when the existingsystem and the evolution system both are based on the three types 0, 1and 2 of uplink-downlink subframe configurations, subframes 3, 4, 8 and9 can be considered to be flexible subframes. Therefore, theconfiguration of the flexible subframe according to the presentinvention can be achieved by notifying user equipment in the evolutionsystem of the uplink-downlink subframe configuration.

Referring to FIG. 1, in a first embodiment of the present invention, amethod, provided for implementing the first embodiment, may comprise thefollowing steps:

Step 101: A base station determines the subframe number of a flexiblesubframe in a radio frame.

The base station determining the subframe number of a flexible subframemeans that the base station determines which subframes are flexiblesubframes. A radio frame in the LTE TDD system includes ten subframes,and which subframes therein are flexible subframes needs to bedetermined by the base station, or which subframes in a plurality ofradio frames are flexible subframes needs to be determined by the basestation. It should be noted that, there are two manners of determiningthe subframe number of a flexible subframe for the base station:

First Manner: the base station determines, according to a predefinedsubframe number of the flexible subframe, the subframe number of aflexible subframe in the radio subframe.

Referring to FIG. 2, which is a schematic diagram of a dynamic TDDsubframe configuration in a radio frame, Nos. 3, 4, 8 and 9 subframes ineach radio frame are flexible subframes. At this time, Nos. 3, 4, 8 and9 subframes in each radio frame need to be predefined as flexiblesubframes at both the base station side and user equipment side.Meanwhile, since the TDD system has seven types of uplink-downlinkconfigurations and the flexible-subframe configuration in each type ofuplink-downlink configuration can be different, the subframe number ofthe flexible subframe in each type of uplink-downlink configuration canbe predefined for each type of uplink-downlink configuration.

Second manner: the base station configures the subframe number of aflexible subframe.

In particular, the base station can autonomously configure the subframenumber of a flexible subframe, according to the current channelenvironment and traffic amount and etc.

It should be noted that, the base station doesn't need to notify theuser equipment of the subframe number of the flexible subframe if thefirst manner is adopted, and the base station still needs toadditionally send a signaling to notify the user equipment if the secondmanner is adopted, because the subframe number of the flexible subframeis variable. The signaling can be carried via a downlink control channelor a higher layer signaling. Preferably, the base station can adopt ahigher layer signaling, so as to improve the reliability. Where, ahigher layer signaling (High layer Signaling), compared to a physicallayer signaling, is a signaling from a higher layer (layer) with aslower transmission frequency, including a radio resource control (RRC,Radio Resource Control) signaling and a media access control (MAC, MediaAccess Control) signaling and a broadcast signaling and so on.

Step 102: The base station determines the feature of the flexiblesubframe corresponding to the subframe number, where the featureindicates that the flexible subframe is an uplink subframe or a downlinksubframe.

After determining the subframe number of the flexible subframe, the basestation can further configure the feature of the flexible subframecorresponding to the determined subframe number, that is, configure eachflexible subframe to be either an uplink subframe or a downlinksubframe.

Step 103: The base station sends to a user equipment a first signalingvia a downlink control channel, where the first signaling includes thefeature of the flexible subframe corresponding to the subframe number.

The downlink control channel in this step refers to a channel within adownlink control region, which can include a physical downlink controlchannel (Physical Downlink Control channel, PDCCH), a physicalhybrid-ARQ indicator channel (Physical hybrid-ARQ indicator channel,PHICH) or a physical control format indicator channel (Physical controlformat indicator channel, PCFICH) and so on. The downlink control regionis the first 1 to 4 orthogonal frequency division multiplexing(Orthogonal Frequency Division Multiplexing, OFDM) symbols in eachsubframe, and can be indicated via the PCFICH.

In this step, the number of bits for indicating the feature of theflexible subframe in the first signaling can be determined according toany of the following parameters: number of the flexible subframesincluded in the repeating period, number of the flexible subframesincluded in the radio frame or number of the flexible subframes includedin an updatable period of the first signaling, and because somesignaling periods cannot be updated, the updatable period refers to theperiod of the first signaling which can be updated. One bit can be usedto indicate the feature of one flexible subframe, for example, “0”indicates an uplink subframe, and “1” indicates a downlink subframe,alternatively, “1” indicates the uplink subframe, and “0” indicates thedownlink subframe. Referring to FIG. 2, there are 2 flexible subframesin a repeating period of 5 milliseconds (ms), and then 2 bits areneeded; or there are 4 flexible subframes in a radio frame of 10 ms, andthen 4 bits are needed, or the updatable period of the signaling is 20ms, so 8 bits are needed because 8 flexible subframes are included.

It should be noted that, in order to save network overhead, one bit alsocan indicate the feature of a plurality of flexible subframes, forexample, one bit indicates the feature of all the flexible subframes inone repeating period, and then “0” indicates all the flexible subframesin one repeating period are uplink subframes, and “1” indicates all theflexible subframes in one repeating period are downlink subframes; or,“1” indicates all the flexible subframes in one repeating period areuplink subframes, and “0” indicates all the flexible subframes in onerepeating period are downlink subframes.

Furthermore, optionally, when the subframe number of the flexiblesubframe is also indicated via the downlink control channel, the firstsignaling can further include a subframe number indication of theflexible subframe.

The first signaling can be a dynamic notification, a periodicnotification or a semi-persistent (Semi-Persistent) notification. Theconfiguration of the flexible subframe is more flexible when the dynamicnotification is adopted; reliability can be improved and the overhead issaved when the periodic notification is adopted; and the overhead can besaved and the configuration of the flexible subframe is flexible whenthe semi-persistent notification is adopted. Where, the semi-persistentnotification means that the base station configures a first signalingand sends it to a user equipment only when the configuration of theflexible subframe is updated. It should be noted that, when the numberof bits needed by the first signaling is determined according to thenumber of the flexible subframes included in the repeating period or theradio frame, the updating period of the signaling is at least therepeating period or a length of the radio frame.

In this embodiment, the feature of the flexible subframe configured bythe base station can be sent to the user equipment via the downlinkcontrol channel, thus the problem in the prior art that the userequipment cannot be notified of the configuration of the flexiblesubframe via the signaling can be solved, and meanwhile the reliabilityof the signaling is relatively high, allowing the user equipment toaccurately acquire the configuration of flexible subframe. Where, theconfiguration of the flexible subframe can include the subframe numberconfiguration of the flexible subframe and the feature configuration ofthe flexible subframe. Further, channel and signal configuration of theflexible subframe can also be included, which will be described indetail in the next embodiment.

Referring to FIG. 3, in a second embodiment of the present invention,the downlink control channel is a physical downlink control channel, amethod, provided for implementing the second embodiment, can include thefollowing steps:

Step 301: A base station determines the subframe number of a flexiblesubframe.

Step 302: The base station determines the feature of the flexiblesubframe corresponding to the subframe number, where the featureindicates that the flexible subframe is an uplink subframe or a downlinksubframe.

Step 303: The base station determines channel and signal configurationof the flexible subframe.

After determining the feature of the flexible subframe, the base stationcan further determine which channel and signal need to be configured onthe flexible subframe.

When the flexible subframe is an uplink subframe, the base station needsto determine whether the flexible subframe is configured with a physicaluplink control channel (PUCCH, Physical Uplink Control Channel), asounding reference signal (SRS, Sounding Reference Signal) and so on;when the flexible subframe is a downlink subframe, the base stationneeds to determine whether the flexible subframe is configured with aPDCCH, a PHICH, a PCFICH, a common reference signal (CRS, CommonReference Signal), a channel state information reference signal (CSI RS,Channel State Information Reference Signal) and so on.

After determining the channel and signal configuration of the flexiblesubframe, the base station needs to send a signaling to notify the user.The content of the signaling includes which channel and signal areconfigured on the flexible subframe, and channel and signal resourceconfiguration. The signaling for the channel and signal configuration ofthe flexible subframe can be carried via the following manners:

-   -   First manner: carried via a downlink control channel;    -   Second manner: carried via a higher layer signaling;    -   Third manner: carried via a combination of a downlink control        channel and a higher layer signaling.

For the third manner, in practical application, for example, whichchannel and signal are configured on the flexible subframe can becarried via the downlink control channel, and the channel and signalresource configuration can be carried via the higher layer signaling.

Optionally, when the channel and signal configuration of the flexiblesubframe is also indicated via the downlink control channel, the firstsignaling can further include the channel and signal configuration ofthe flexible subframe.

Step 304: The base station sends to a user equipment a first signalingvia the downlink control channel, where the first signaling includes thefeature of the flexible subframe, the subframe number of the flexiblesubframe, and the channel and signal configuration.

As a practical application example, the first signaling in step 304simultaneously includes the feature of the flexible subframe, thesubframe number of the flexible subframe, and the channel and signalconfiguration. In other examples, besides always including the featureof the flexible subframe, the first signaling can include both thesubframe number and the channel and signal configuration, or includeneither the subframe number nor the channel and signal configuration, orinclude only the subframe number or the channel and signalconfiguration. In the practical application, the first signaling in step304 particularly can be carried via different channels, and also caninclude different processing mechanisms for different channel types.

First mechanism: the first signaling is carried via the PDCCH.

Prior to receiving or sending traffic data, the user equipment needs toknow downlink control information (Downlink Control Information, DCI)configured by a eNB for the user equipment. DCI includes a variety offormats. DCI is carried via the PDCCH. A PDCCH set to be detected by theUE is called a search space.

The false alarm (FA, False Alarm) on cyclic redundancy check (CRC,Cyclic Redundancy Check) of PDCCH will cause the user equipment tomisunderstand the current flexible subframe feature. In all the existingDCI formats, the downlink control information (Downlink ControlInformation, DCI) bit number (DCI payload, DCI payload size) isrelatively big, however, the DCI for indicating the feature of theflexible subframe in dynamic TDD only needs a few bits, so the resourcewaste is relatively large. Therefore, embodiments of the presentinvention, in order to design a reliable and overhead-saving DCI,provide the following manners:

First manner: the base station configures the same downlink controlinformation for at least two user equipments.

The base station configures a same radio network temporary identifier(RNTI, Radio Network Temporary Identifier) for at least two userequipments. Preferably, the DCI is carried on a PDCCH within a commonsearch space. The base station can send the same downlink controlinformation to the user equipment via the physical downlink controlchannel within the common search space, to facilitate the user equipmentto acquire the first signaling via the indicating bit in the downlinkcontrol information. Further, since the existing common search space hasa limited capacity, the size of the common search space can be extended,particularly to an extent, which can be predefined by a standard orconfigured via a higher layer signaling.

If the first manner is adopted, the object of notifying the userequipment of the feature of the flexible subframe via signaling can beachieved, and meanwhile the overhead can be reduced significantly, forexample, if it originally needs to send five pieces of DCI to five userequipments, however, when the method of this embodiment is adopted, onlyone piece of DCI needs to be sent, and the five user equipments all canlisten to the same DCI, so that more control channel transmissionresources can be saved.

Second manner: the base station configures the first signaling carriedon one or more than one reserved bit of the downlink controlinformation, and sends the downlink control information to the userequipment via the physical downlink control channel.

In the second manner, the way of reserving bits in the existing DCIformats to indicate the first signaling is adopted. Preferably, the DCIin the common search space is adopted to indicate the first signaling.For example, at least one format is selected out of DCI format 3, DCIformat 3A and DCI format 1A.

When the DCI in the common search space is the DCI format 1A scrambledby a system information radio network temporary identity (SI-RNTI,System Information RNTI), a P-RNTI (Paging RNTI) or a random access RNTI(RA-RNTI, Random Access RNTI), in the TDD system, there are 5 redundantbits or reserved bits (reserved bits) in the DCI format 1A, which can beused for indicating the first signaling.

When the DCI in the common search space is the DCI format 3, one or morethan one bit field is reserved in the DCI format 3, for indicating thefirst signaling. The particular number of the reserved bits is thenumber of bits needed for configuring the first signaling, for example,when the first signaling only includes the feature of the flexiblesubframe, and 4 bits are needed to indicate, then 4 bits are reserved.The DCI format 3 includes a plurality of bit fields, each bit fieldincludes 2 bits and is identified by a transmit power control index(TPC-Index, Transmit Power Control Index).

The bit fields reserved in the DCI format 3 for indicating the firstsignaling may be indicated by way of following manners. Manner {circlearound (1)}, configuring the reserved bit fields via the higher layersignaling. A reserved TPC-Index can particularly be configured, forexample, the base station configures reserved TPC-Indexes 1 and 2 for agroup of user equipments, with a total of 4 bits, the configuration viathe higher layer signaling is flexible and can improve the useefficiency of the bit fields. Manner {circle around (2)}, predefiningthe reserved bit fields. In this way, no additional signalingconfiguration is needed, but the reserved bit fields are fixed.Furthermore, when the DCI bit number of the DCI format 3 is an oddnumber, there is 1 redundant bit, which can be used for indicating thefirst signaling.

The RNTI used to scramble the CRC field in the DCI format 3 isTPC-PUCCH-RNTI or TPC-PUSCH-RNTI. When the first signaling is indicatedvia the reserved bit fields in the DCI format 3, even if the userequipment has no need to monitor the TPC in the DCI format 3, the basestation also needs to configure and notify the user equipment of theRNTI used to scramble the CRC field in the DCI format 3. When the userequipment needs to monitor the TPC in the DCI format 3, the RNTI of theDCI format 3 used to acquire the TPC and the RNTI of the DCI format 3used to acquire the first signaling are configured to be the same, thatis, the user equipment can acquire TPC and the first signaling bymonitoring one same DCI format 3. Such can reduce the average number ofPDCCH blind detection attempts, because when the RNTI of the DCI format3 used to acquire TPC and the RNTI of the DCI format 3 used to acquire adynamic TDD subframe configuration are different, the user equipmentneeds to monitor two DCI format 3s scrambled by different RNTIs, leadingto an increase on the average number of PDCCH blind detection attempts.

When the DCI in the common search space is the DCI format 3A, theparticular configuration manner is similar to the case of the DCI format3. One or more than one bit field is reserved in the DCI format 3A, forindicating the first signaling. The particular number of the reservedbits is the number of bits needed by the first signaling. The DCI format3A includes a plurality of bit fields, each bit field includes 1 bit andis identified by a transmit power control index (TPC-Index, TransmitPower Control Index).

In the DCI format 3A the bit fields reserved for indicating the firstsignaling can be indicated by way of the following manners. Manner{circle around (1)}, configuring the reserved bit fields via the higherlayer signaling, where reserved TPC-Indexes can particularly beconfigured. Manner {circle around (2)}, predefining the reserved bitfields. The RNTI used to scramble the CRC field in the DCI format 3A isTPC-PUCCH-RNTI or TPC-PUSCH-RNTI. When the first signaling is indicatedvia the reserved bit fields in the DCI format 3A, even if the userequipment has no need to monitor the TPC in the DCI format 3A, the basestation also needs to configure and notify the user equipment of theRNTI used to scramble the CRC field in the DCI format 3A. When the userequipment needs to monitor the TPC in the DCI format 3, the RNTI of theDCI format 3A used to acquire the TPC and the RNTI of the DCI format 3Aused to acquire the first signaling are configured to be the same, thatis, the user equipment can acquire the TPC and the first signaling bymonitoring one same DCI format 3A.

It should be noted that, to reduce the average number of the PDCCH blinddetection attempts, the TPC information and the first signaling whichare need to be acquired by the same user equipment are carried by thesame PDCCH, that is, the adopted DCI formats are the same (either theDCI format 3 or the DCI format 3A), and the adopted RNTIs are the same,in this way, the same user equipment can acquire the TPC information andthe first signaling by monitoring only one same DCI.

In order to improve the reliability and reduce the probability of a CRCfalse alarm, bit fields can be reserved in the DCI to be used as avirtual CRC, that is, the virtual CRC is set to be a particular value,and the user equipment performs further check to determine whether it isthe set value after receiving the DCI.

Third manner: the base station generates a new DCI format, forindicating the first signaling. The base station sends thenewly-generated downlink control information to the user equipment viathe physical downlink control channel.

Because the first signaling only needs few bits, there are two mannersto reduce the overhead:

Manner {circle around (1)}: the DCI format only includes the firstsignaling and CRC information. In order to improve reliability andreduce the probability of a CRC false alarm, the virtual CRC informationalso can be included. For example, the DCI includes the first signalingof 4 bits or 9 bits, where the first signaling of 4 bits only includesthe feature configuration of the flexible subframe, and the firstsignaling of 9 bits includes the feature configuration of the flexiblesubframe and the channel and signal configuration; the virtual CRCinformation of 6 bits and the CRC information of 16 bits, and thus 26bits are needed altogether. In the existing DCI formats, the DCI format1C has the smallest number of information bits, and the number of theinformation bits of the DCI format for indicating the dynamic TDDsubframe configuration can be the same as that of the DCI format 1C soas not to increase the number of blind detection attempts. If less thanthe number of bits of the DCI format 1C, for example, the DCI format 1Ccorresponding to 20 MHz is 31 bits, the DCI format for indicating thedynamic TDD subframe configuration is 26 bits, and then redundantinformation bits (i.e., reserved bits) are added, or the virtual CRCbits are lengthened, to make both of the two formats be 31 bits. The DCIformat also can be configured to only adopt CCE aggregation levels of 4or 8 to improve the performance.

Manner {circle around (2)}: the DCI format can indicate otherinformation in addition to the first signaling, such as PDCCH blinddetection information (for reducing the number of the blind detectionattempts of the user equipment), and PDCCH precoding (Precoding)information.

It should be noted that, the first manner in the first mechanism can beused in combination with the second manner or the third manner. Forexample, when the first manner and the second manner are used incombination, the TPC information and the first signaling which areneeded to be acquired by the at least two user equipments are configuredto be carried by the same PDCCH.

Where, in step 304, the first signaling can be carried via otherprocessing mechanisms.

Second mechanism, the downlink control channel is the physicalhybrid-ARQ indicator channel, and the first signaling is carried via thePHICH.

A PHICH resource is identified by n_(PHICH) ^(group) and n_(PHICH)^(seq), where, n_(PHICH) ^(group) indicates a PHICH group number, andn_(PHICH) ^(seq) indicates an orthogonal sequence number in a PHICHgroup.

In particular, in the second mechanism, the base station predefinesreserved physical hybrid-ARQ indicator channel resources or notifies theuser equipment of physical hybrid-ARQ indicator channel resources viathe third signaling notification message.

In this embodiment, the reserved PHICH resources can be adopted to carrythe first signaling. Where, the reserved PHICH resources cannot be usedas an HARQ indicator (HI, HARQ indicator). The reservation manner can beas follows:

First manner: predefine the reserved PHICH resources. In particular, thereserved PHICH resources can be defined via n_(PHICH) ^(group) andn_(PHICH) ^(seq). When the PHICH resources are not reserved in all thesubframes, the subframe number of the subframe in which the PHICHresource is reserved also needs to be defined. For example, the PHICHresources in Nos. 0, 1, 5 and 6 subframes of each radio frame aredefined to be reserved for carrying the first signaling. For a PHICHwhen one downlink subframe corresponds to two uplink subframes, thetotal PHICH resources may be doubled, at this time, the PHICH resourcesare divided into two parts, I_(PHICH) identifier can be introduced toindicate a particular part. Therefore, it also needs to be defined towhich part of the PHICH resources the reserved PHICH resources belong,and particularly a reserved I_(PHICH) is defined.

Second manner: the base station signals the user equipment of thereserved PHICH resources. Preferably, the higher layer signaling isadopted for notification. In particular, the reserved n_(PHICH) ^(group)and n_(PHICH) ^(seq) can be notified. When the PHICH resources are notreserved in all the subframes, the subframe number of the subframe inwhich the PHICH resource is reserved also needs to be signaled. Forexample, the PHICH resources in Nos. 0, 1, 5 and 6 subframes of eachradio frame are reserved for carrying the dynamic TDD subframeconfiguration signaling. For a PHICH when one downlink subframecorresponds to two uplink subframes, the reserved I_(PHICH) also needsto be notified, where the signaling used by the base station to notifythe user equipment in the second manner is the aforementioned thirdsignaling notification message.

In this embodiment, the method of mapping the first signaling to thereserved PHICH resources is to encode the first signaling based on thereserved PHICH resources in one or more subframes. For example, thefirst signaling is originally 2 bits, 6 PHICH resources are reserved ina subframe, and the TDD subframe configuration signaling can be encodedto 6 bits and carried respectively via the 6 PHICH resources. Theencoding can be a simple repetition encoding or other encoding method.

Step 304 also can be implemented by way of a third mechanism: the firstsignaling is carried via the PCFICH.

In particular, when the third mechanism is implemented, a reserved state4 of the PCFICH can be adopted to indicate the first signaling.

Step 304 also can be implemented by way of a fourth mechanism: the firstsignaling is carried via one or more than one redundant REG.

In general, a redundant resource-element group (REG, Resource-elementgroup) may occur in the downlink control region. The redundant REG canbe used for carrying the first signaling, and the first signaling isencoded according to the size of the redundant REG resource.

It should be noted that, in practical application of the presentinvention, the subframe number of the flexible subframe and the featurethereof, as well as the channel and signal configuration of the flexiblesubframe can be configured by way of broadcasting. Where, thebroadcasting message can take the form of master information block (MIB,Master Information Block) or system information block (SIB, SystemInformation Block). When carrying via MIB, redundant bits in the MIB canbe used to notify the user. When carrying via SIB, new IE needs to beadded.

It should be noted that, for simplicity of description, the above methodembodiments are described as a series of operations, but it should beappreciated by persons skilled in the art that the present inventionisn't restricted by the described operation sequence, since some stepscan be implemented by other sequence or simultaneously according to thepresent invention. Also, it should be appreciated by persons skilled inthe art that the embodiments described in the specification belong topreferred options, so the associated operations and units are notnecessarily essential to the present invention.

Corresponding to the method provided by the above embodiments, referringto FIG. 4, embodiments of the present invention also provide a schematicstructural diagram of a base station applied to a time division duplexsystem, and the base station particularly can include:

a first processing unit 401, configured to determine the subframe numberof a flexible subframe in a radio frame;

a second processing unit 402, configured to determine the feature of theflexible subframe corresponding to the subframe number determined by thefirst processing unit, where the feature indicates that the flexiblesubframe is an uplink subframe or a downlink subframe.

a sending unit 403, configured to send to a user equipment a firstsignaling via a downlink control channel, where the first signalingincludes the feature of the flexible subframe corresponding to thesubframe number and the feature of the flexible subframe is determinedby the second processing unit.

In different practical applications or embodiments, as shown in FIG. 5,the base station can further include:

a third processing unit 501, configured to determine channel and signalconfiguration of the flexible subframe corresponding to the subframenumber determined by the first processing unit;

then the sending unit 403, further configured to notify the userequipment of the channel and signal configuration determined by thethird processing unit via the first signaling or a higher layersignaling.

In practical application, the channel and signal configuration can besent to the user equipment via the downlink control channel or thehigher layer signaling. It should be noted that, when the channel andsignal configuration is sent to the user equipment via the downlinkcontrol channel, as a practical application example, the channel andsignal configuration of the flexible subframe also can be sent to theuser equipment by the sending unit 403 via the first signaling.

In another embodiment, the base station can further include:

the sending unit, further configured to notify the user equipment of thesubframe number of the flexible subframe via the first signaling or ahigher layer signaling.

Where, the subframe number of the flexible subframe can be notified tothe user equipment via the downlink control channel or the higher layersignaling. When the subframe number is sent to the user equipment viathe downlink control channel, the channel and signal configuration canbe sent to the user equipment by the sending unit via the firstsignaling.

Different sending unit 403 can be used depending on the downlink controlchannel, in another embodiment, when the downlink control channel is aphysical downlink control channel, as shown in FIG. 6, the sending unit403 particularly can include:

a configuring subunit 601, configured to configure same downlink controlinformation for at least two user equipments; where bits of the downlinkcontrol information include one or more than one bit indicating thefirst signaling;

a first sending subunit 602, configured to send the same downlinkcontrol information to the user equipment via the physical downlinkcontrol channel within a common search space, to facilitate the userequipment to acquire the first signaling via the one or more than oneindicating bit in the downlink control information.

In another embodiment, when the downlink control channel is a physicaldownlink control channel, as shown in FIG. 7, the sending unit 403particularly can include:

a first carrying subunit 701, configured to carry the first signaling onone or more than one reserved bit of the downlink control information,where the downlink control information is formed in at least one formatof DCI format 3, DCI format 3A and DCI format 1A;

a second sending subunit 702, configured to send the downlink controlinformation to the user equipment via the physical downlink controlchannel.

In another embodiment, when the downlink control channel is a physicalhybrid-ARQ indicator channel, as shown in FIG. 8, the sending unit 403particularly can include:

a second carrying subunit 801, configured to carry the first signalingon reserved resources of the physical hybrid-ARQ indicator channel; and

a second sending subunit 802, configured to send to the user equipmentthe first signaling on the physical hybrid-ARQ indicator channelresources.

In practical application, the base station also can include: a dataprocessing unit, configured to receive traffic data of a current radioframe sent by the user equipment according to the first signaling; or,send traffic data of the current radio frame to the user equipmentaccording to the first signaling.

Referring to FIG. 9, which shows a flow chart of a method for subframeconfiguration applied to a time division duplex system according to anembodiment of the present invention, and the method, when applied to aterminal in the time division duplex system, particularly can include:

Step 901: A user equipment acquires the subframe number of a flexiblesubframe.

When acquiring the subframe number of a flexible subframe, the userequipment can determine the subframe number of the flexible subframe byreceiving the signaling notification of the base station, and can alsodetermine by way of predefining the subframe number of the flexiblesubframe.

The process of determining the subframe number of the flexible subframeby the base station has been described in detail in the firstembodiment, and no further details are given here.

Step 902: The user equipment receives a first signaling sent by a basestation via a downlink control channel, where the first signalingincludes the feature of the flexible subframe corresponding to thesubframe number, and the feature indicates that the flexible subframe isan uplink subframe or a downlink subframe.

Step 903: According to the received first signaling, acquire the featureof the flexible subframe corresponding to the subframe number.

In various embodiments, after receiving the feature of the flexiblesubframe, the user equipment also can receive channel and signalconfiguration of the flexible subframe sent by the base station via thedownlink control channel and/or a high level signaling. Optionally, whenthe channel and signal configuration of the flexible subframe is alsoindicated via the downlink control channel, the first signaling furtherincludes the channel and signal configuration of the flexible subframe.

In various embodiments, prior to determining the feature of the flexiblesubframe, the user equipment also can receive the subframe number of theflexible subframe notified by the base station via the downlink controlchannel or the high level signaling. Optionally, when the subframenumber of the flexible subframe is also indicated via the downlinkcontrol channel, the first signaling further includes the subframenumber of the flexible subframe.

It should be noted that, because the process of the method at the userequipment side is related to the process of the method at the basestation side, except that the base station side is a transmitting end ofthe first signaling and the user equipment side is a receiving end ofthe first signaling, therefore, the contents relevant to the firstsignaling and different mechanisms of the user equipment on the downlinkcontrol channel can refer to the foregoing description on the basestation side.

In this embodiment, the feature of the flexible subframe configured bythe base station can be received via the downlink control channel, thusthe problem in the prior art that the user equipment cannot be notifiedof the configuration of the flexible subframe via the signaling can besolved, and meanwhile the reliability of the signaling is relativelyhigh, allowing the user equipment to accurately acquire theconfiguration of the flexible subframe. Where, the configuration of theflexible subframe can include the subframe number configuration of theflexible subframe and the feature configuration of the flexiblesubframe. Further, the channel and signal configuration of the flexiblesubframe also can be included.

Referring to FIG. 10, which is a schematic structural diagram of a userequipment applied in a time division duplex system according to thepresent invention, the user equipment can include:

a fourth processing unit 1001, configured to determine the subframenumber of a flexible subframe;

a receiving unit 1002, configured to receive, after a base stationdetermines the feature of the flexible subframe in a current radioframe, a first signaling sent by the base station via a downlink controlchannel, where the first signaling includes the feature of the flexiblesubframe corresponding to the subframe number, and the feature indicatesthat the flexible subframe is an uplink subframe or a downlink subframe.

an acquiring unit 1003, configured to acquire, according to the receivedfirst signaling, the feature of the flexible subframe corresponding tothe subframe number.

In various embodiments, the receiving unit further can be configured toreceive channel and signal configuration of the flexible subframe sentby the base station via the first signaling and/or a high levelsignaling. Optionally, when the channel and signal configuration of theflexible subframe is also indicated via the downlink control channel,the first signaling can further include the channel and signalconfiguration of the flexible subframe.

In various embodiments, the receiving unit further can be configured toreceive the subframe number of the flexible subframe notified by thebase station via the first signaling or a high level signaling.Optionally, when the subframe number of the flexible subframe is alsoindicated via the downlink control channel, the first signaling canfurther include a subframe number of the flexible subframe.

Embodiments of the present invention provide another embodiment of amethod for subframe configuration in a time division duplex system,applied at the base station side, referring to FIG. 11, the method forimplementing embodiments of the present invention can include thefollowing steps:

Step 1101: A base station sends a second signaling to a user equipmentof an evolution version, where the second signaling indicates anuplink-downlink subframe configuration.

The uplink-downlink subframe configuration indicated by the secondsignaling can be different from the uplink-downlink subframeconfiguration notified to a user equipment of a non-evolution version(such as, LTE Rel-8/9/10). For example, the uplink-downlink subframeconfiguration currently notified to a user equipment of a non-evolutionversion is 2, while the uplink-downlink subframe configuration notifiedto a user equipment of an evolution version is 1. In this way, not onlythe compatibility of the existing versions can be guaranteed, but alsothe uplink-downlink subframe configuration in an evolution version canbe changed flexibly based on the uplink-downlink traffic demands.

For a user equipment of a non-evolution version (such as, LTERel-8/9/10), the system notifies the current seven types ofuplink-downlink subframe configurations via a broadcast signaling.

For a user equipment in an evolution system (such as LTE Rel-11/12), thebase station can semi-statically or dynamically notify the currentuplink-downlink subframe configuration (which can be the existing seventypes of configurations, also can be a newly added uplink-downlinksubframe configuration) via a higher layer signaling or a downlinkcontrol channel. The frequency of the notification can be periodic orsemi-persistent. In particular, when the higher layer signaling isadopted, RRC signaling or MAC signaling can be used so that the currentuplink-downlink subframe configuration of the user equipment can berespectively configured, for example, some user equipments of anevolution version can be notified to adopt a uplink-downlink subframeconfiguration which is different from the uplink-downlink subframeconfiguration of the user equipments of an existing version, and also,user equipments of different evolution versions can be configured withdifferent uplink-downlink subframe configurations. When the physicaldownlink control channel is adopted, the method provided in step 304 ofthe second embodiment (except that the first signaling is carried in thesecond embodiment, and the second signaling is carried in thisembodiment) can be used to carry the second signaling via PDCCH, orPHICH, or PCFICH, or redundant REG.

In addition, the base station can configure a valid time (duration) ofthe second signaling, the minimum unit of the valid time can be at aradio frame level (10 ms for one radio frame), for example, the basestation configures that the current second signaling is valid within 100radio frames or 50 radio frames; the minimum unit also can be at themillisecond (ms) level, for example, the base station configures thatthe current second signaling is valid within 100 ms or 1000 ms. Themethod for configuring and notifying a valid time of the secondsignaling can specifically include the following methods:

First method, the valid time of the second signaling is notified via ahigher layer signaling. In particular, RRC signaling or MAC signalingcan be used. When the second signaling is notified via the higher layersignaling, the notification of the valid time can be sent together withthe second signaling.

Second method, the valid time of the second signaling is notified via aphysical downlink control channel. When the second signaling is notifiedvia the physical downlink control channel, the notification of the validtime can be sent together with the second signaling.

Third method, predefine. The valid time of the second signaling can bepredefined in a standard, such as 100 radio frames.

In this embodiment, the uplink-downlink subframe configuration of theuser equipment of an evolution version can be separately indicated viathe higher layer signaling or the downlink control channel, thus theproblem in the prior art that the user equipment cannot be notified ofthe configuration of the flexible subframe via the signaling can besolved, and meanwhile the reliability of the signaling is relativelyhigh, allowing the user equipment to accurately acquire theconfiguration of the flexible subframe.

Corresponding to the method provided by the above embodiment,embodiments of the present invention also provide a base station appliedto a time division duplex system, referring to FIG. 12, and the basestation particularly can include:

a second signaling sending unit 1201, configured to send a secondsignaling to a user equipment of an evolution version, where the secondsignaling indicates an uplink-downlink subframe configuration.

When the base station also needs to notify a valid time of the secondsignaling via a higher layer signaling or a physical downlink controlchannel, referring to FIG. 13, the base station side also includes:

a notifying unit 1301, configured to notify a valid time of the secondsignaling to the user equipment of the evolution version.

Corresponding to the method provided by the above embodiment,embodiments of the present invention provide another embodiment of themethod for subframe configuration in a time division duplex system,applied at the user equipment side, referring to FIG. 14, the method forimplementing embodiments of the present invention can include thefollowing steps:

Step 1401: A user equipment of an evolution version receives a secondsignaling sent by a base station, where the second signaling indicatesan uplink-downlink subframe configuration.

The uplink-downlink subframe configuration indicated by the secondsignaling can be different from the uplink-downlink subframeconfiguration notified to the user equipment of a non-evolution version(such as, LTE Rel-8/9/10). The user equipment of an evolution versioncan semi-statically or dynamically know the uplink-downlink subframeconfiguration via a higher layer signaling or a downlink controlchannel.

In addition, the user equipment in the evolution version needs toacquire a valid time (duration) of the second signaling. The particularmethod for acquiring a valid time of the second signaling can includethe following methods:

First method, receiving a higher layer signaling and acquiring a validtime of the second signaling.

Second method, receiving a physical downlink control channel andacquiring a valid time of the second signaling.

Third method, predefining.

Corresponding to the method provided by the above embodiment,embodiments of the present invention also provide a user equipmentapplied to a time division duplex system, referring to FIG. 15, and theuser equipment particularly can include:

a second signaling receiving unit 1501, configured to receive a secondsignaling sent by a base station, where the second signaling indicates auplink-downlink subframe configuration. Such unit is only configured onthe user equipment of an evolution version.

When the user equipment also needs to acquire a valid time of the secondsignaling via a higher layer signaling or a physical downlink controlchannel, referring to FIG. 16, the user equipment also includes:

an acquiring unit 1601, configured to received a higher layer signalingor a physical downlink control channel and acquire a valid time of thesecond signaling. Such unit is only configured on the user equipment ofan evolution version.

It should be noted that all embodiments in the specification aredescribed in a progressive way, each embodiment mainly describes thedifferences from other embodiments, so the equivalent or similar partsamong the embodiments can be referenced mutually. The embodiments of thedevice and the system are described relatively simple because theycorrespond to the method embodiments basically, and related parts mayrefer to the descriptions of the corresponding parts in the methodembodiments.

It should be noted that, the terms “comprise”, “include” or anyvariations thereof as used herein are intended to cover a non-exclusiveinclusion, so that a process, method, article, or apparatus thatcomprises a list of elements does not include only those elements butmay include other elements not expressly listed or inherent to suchprocess, method, article, or apparatus. An element defined by “comprisesa . . . ”, without more constraints, does not preclude the existence ofadditional identical elements in the process, method, article, orapparatus that comprises the element.

It should be appreciated by persons skilled in the art that, all or apart of the steps in the method of the above embodiments may becompleted by relevant hardware under the instruction of a program, andthe program may be stored in a computer readable storage medium, such asa read only memory (ROM), a random access memory (RAM), a floppy disk,or an optical disk.

The method, the base station and the user equipment for subframeconfiguration in a time division duplex provided by embodiments of thepresent invention have been described in detail above, in the presentinvention the particular examples are used to explain the principle andembodiments of the present invention, and the above description ofembodiments is merely intended to facilitate understanding the methodsin the embodiments of the invention and concept thereof; meanwhile, itis apparent to persons skilled in the art that changes can be made tothe particular implementation and application scope of the presentinvention based on the concept of the embodiments of the invention, inview of the above, the contents of the specification shall not beconsidered as a limitation to the present invention.

What is claimed is:
 1. A method for subframe configuration in a timedivision duplex system, comprising: determining, by a base station, asubframe number of a flexible subframe in a radio frame; determining, bythe base station, a feature of the flexible subframe corresponding tothe subframe number, wherein the feature indicates that the flexiblesubframe is an uplink subframe or a downlink subframe; and sending, bythe base station, to a user equipment downlink control information (DCI)via a physical downlink control channel within a common search space,wherein the DCI includes a first signaling that indicates the feature ofthe flexible subframe corresponding to the subframe number, and a numberof information bits of the DCI is the same as that of DCI format 1C. 2.The method according to claim 1, further comprising: determining, by thebase station, channel and signal configuration of the flexible subframecorresponding to the subframe number; and notifying, by the basestation, the user equipment of the determined channel and signalconfiguration via the physical downlink control channel and/or a higherlayer signaling.
 3. The method according to claim 1, further comprising:notifying, by the base station, the user equipment of the subframenumber of the flexible subframe via the physical downlink controlchannel or a higher layer signaling.
 4. The method according to claim 1,wherein the sending, by the base station, to the user equipment the DCIvia the physical downlink control channel within the common search spacecomprises: configuring, by the base station, the same DCI for at leasttwo user equipments, wherein bits of the DCI include one or multiplebits for indicating the first signaling; and sending, by the basestation, the same DCI to the user equipment via the physical downlinkcontrol channel within a common search space, to facilitate the at leasttwo user equipments to acquire the first signaling via the one ormultiple bits in the DCI.
 5. A method for subframe configuration in atime division duplex system, the method comprising: acquiring, by a userequipment, a subframe number of a flexible subframe; receiving downlinkcontrol information (DCI) sent by a base station via a physical downlinkcontrol channel within a common search space, wherein the DCI includes afirst signaling that indicates a feature of the flexible subframecorresponding to the subframe number, and the feature indicates that theflexible subframe is an uplink subframe or a downlink subframe, and anumber of information bits of the DCI is the same as that of DCI format1C; acquiring, according to the received first signaling, the feature ofthe flexible subframe corresponding to the subframe number.
 6. Themethod according to claim 5, further comprising: receiving, by the userequipment, channel and signal configuration of the flexible subframecorresponding to the subframe number via the physical downlink controlchannel and/or a higher layer signaling.
 7. The method according toclaim 5, wherein the receiving, by the user equipment, the channel andsignal configuration of the flexible subframe corresponding to thesubframe number via the physical downlink control channel comprisesreceiving, by the user equipment, the first signaling sent by the basestation, wherein the first signaling includes the channel and signalconfiguration of the flexible subframe corresponding to the subframenumber.
 8. The method according to claim 5, further comprising:receiving, by the user equipment, the subframe number via the physicaldownlink control channel or a higher layer signaling.
 9. A userequipment, applied to a time division duplex system, for communicatingwith a base station, the user equipment comprising a processor and anon-transitory computer-readable medium having processor-executableinstructions stored thereon, wherein the processor-executableinstructions, when executed by the processor, include instructions for:determining a subframe number of a flexible subframe; receiving downlinkcontrol information (DCI) sent by a base station via a physical downlinkcontrol channel within a common search space, wherein the DCI includes afirst signaling that indicates a feature of the flexible subframecorresponding to the subframe number determined by the processor, andthe feature indicates that the flexible subframe is an uplink subframeor a downlink subframe, and a number of information bits of the DCI isthe same as that of DCI format 1C; and acquiring, according to the firstsignaling received by the receiver, the feature of the flexible subframecorresponding to the subframe number.
 10. The user equipment accordingto claim 9, wherein the processor-executable instructions furtherincludes instructions for receiving channel and signal configuration ofthe flexible subframe corresponding to the subframe number via the firstsignaling and/or a higher layer signaling.
 11. The user equipmentaccording to claim 9, wherein the processor-executable instructionsfurther includes instructions for receiving the subframe numberdetermined by the processor via the first signaling or a higher layersignaling.